The Strong Heart Study (Cardiovascular Disease in American Indians) is a study of prevalence and incidence of cardiovascular disease (CVD) and its risk factors in 13 American indian tribes/communities in Arizona, Oklahoma, and South and north Dakota. Phase I of the Study (October 1, 1988 - July 31, 1991) had three components; A mortality survey of tribal members aged 35 - 74 years to estimate CVD mortality rates from 1984 - 1988; a physical examination of 1527 volunteers, aged 45 - 74 years, and a morbidity survey of hospitalized myocardial infarction and stroke among the examination cohort in order to estimate the prevalence of CVD and its association with risk factors. In Phase II of the Study (August 1, 1991 - July 31, 1996), the community mortality and cohort morbidity surveys were continued. A mortality surveillance of Phase I was initiated. The living participants of phase I were re-examined. Procedures such as echocardiography, pulmonary function testing, ultrasound examination of the gall-bladder, TB skin testing, and a dietary survey were added to the clinical examination. This application proposes a four-year extension (Phase III) of the Strong Heart Study, in which , the mortality survey will be continued in the Study communities and in the Phase I cohort, and the members of the Phase i cohort will be followed and re-examined. The aims of the new phase are to determine mortality rates for CVD and other causes, and incidence rates of CVD and the relationship between risk factors and CVD, and to compare risk factors and their changes over time in the three geographic areas and relate the changes to rates of CVD. A family study will be added to the Phase III study in which 10 families of approximately 30 adult members each will be recruited and studied for the inheritance of CVD risk factors. Additional aims include to compare CVD risk factors among individuals with and without diabetes, and to investigate carotid arterial wall thickness by using ultrasonography. The Center for Epidemiologic Research at the College of Public Health, University of Oklahoma Health Science Center proposes to continue its participation ti Phase III of the Study as a Field Center and the Coordinating Center.